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Query: EMI
Links: 210 | Categories: 3
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Single Sideband (SSB) operation requires careful attention to the relationship between a radio's displayed frequency (suppressed carrier) and the actual 3 kHz wide audio signal. This resource clarifies how Upper Sideband (USB) and Lower Sideband (LSB) signals occupy spectrum above or below the indicated frequency, respectively. It provides practical examples for General Class operators on the **20m** and **40m** bands, such as setting a VFO to 14.226 MHz for USB on 20m or 7.178 MHz for LSB on 40m, to maintain a safe margin from band edges. The resource emphasizes the critical importance of staying within allocated band limits to prevent out-of-band emissions, particularly when operating close to band edges. It includes relevant excerpts from **FCC Regulation Part 97**, specifically section 97.307, which details emission standards, necessary bandwidth, and spurious emission attenuation requirements. The text explains that unused sidebands are considered spurious emissions and notes that modern HF equipment typically exceeds the 43 dB spurious emission reduction standard, often achieving 60 dB or more.
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Southern California's Premier Repeater System. Intractive map with Analog and Digital mode repeaters in South, Mid and North California
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The Canadian Amateur (TCA), Canada’s premiere national magazine devoted to Amateur Radio, is published six times per year and is the membership journal of the Radio Amateurs of Canada (RAC). It is available in both print and digital versions (eTCA). Members of RAC, Canada’s sole national Amateur Radio organization, receive TCA automatically. A subscription to TCA also provides membership in Radio Amateurs of Canada. RAC is also the publisher of TCA. For information on how to join Radio Amateurs of Canada and subscribe to TCA please visit our Membership Sign Up page.
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Provides access to a robust DX cluster node, G6NHU-2, running DX Spider software, which facilitates real-time amateur radio contact spotting across HF bands. This service is engineered for high reliability and low latency, ensuring rapid dissemination of DX spots from a global network of interconnected nodes. It features multiple redundant links to prevent data loss and maintain continuous operation, even if individual connections drop. The cluster integrates directly with the Reverse Beacon Network (RBN), allowing users to enable or disable skimmer spots for specific modes like CW, RTTY, FT8, and FT4. It also offers an extensive one-year spot history, significantly longer than most other DX clusters, which typically retain only a month of data. The node supports various lookup commands for callsign information, beam headings, QSL routing, and FCC database lookups, enhancing operational efficiency for DXers and contesters. Additionally, it permits self-spotting, a feature increasingly relevant in modern contests, and provides detailed instructions for connecting popular logging software such as N1MM+, HamRadioDeluxe, MacLoggerDX, LOG4OM2, Logger32, and N3FJP's Amateur Contact Log.
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The article describes ongoing issues with a new TS590s transceiver, including intermittent reception and transmission failures. After a repair diagnosed as a "Control Unit interruption," the problem persisted. The author discovered the cause was a poorly crimped CN601 connector on the Control Unit board, leading to signal loss when moved. Soldering the connector resolved the issue. Similar problems reported by other users suggest a potential defect in the cables, pointing to a possible manufacturing issue.
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Off Grid Ham discusses the benefits of mobile ham radio operation in addition to fixed or semi-fixed base stations. The article highlights the challenges of antenna placement on vehicles, emphasizing the importance of a good ground plane for optimal performance. Tradeoffs between performance and appearance are inevitable, especially with modern vehicles that have plastic body panels. Bonding the coax shield to the car frame is often necessary to establish a good ground plane. Mobile ham radio operation is a valuable option that fills in the gaps left by fixed stations, offering flexibility and convenience for hams on the go.
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The project details the construction of a GM3OXX OXO transmitter, designed to accommodate **FT-243 crystals** using 3D-printed FX-243 holders from John KC9ON. It presents specific frequency adjustments, noting a 7030 KHz HC-49/s crystal could be tuned from 7029.8 KHz to 7031.7 KHz with an internal 45pF trimmer capacitor. The build incorporates a modified keying circuit to prevent oscillator run-on key-up and includes a TX/RX switch for sidetone via a connected receiver, with the transmitter output routed to a dummy load on receive. Practical construction aspects are thoroughly covered, including the process of cutting a rectangular opening in a diecast enclosure for the FT-243 socket and the selection of a **low-pass filter** (LPF) based on the QRP Labs kit, derived from the W3NQN design. The author achieved approximately 800mW output power from a 14.75V supply, measured with an NM0S QRPoMeter, using a 16.5-ohm emitter resistor in the 2N3866 final stage. The article also touches upon the potential for frequency agility across the 40M band using multiple FX-243 units with various crystals. The narrative includes a brief diversion into Bob W3BBO's recent homebrew projects, such as his Ugly Weekender MK II transceiver, highlighting the enduring appeal of classic QRP designs. The author reflects on the personal satisfaction derived from building RF-generating equipment, irrespective of DX achievements, and shares experiences of making local contacts with the 800mW OXO transmitter on 40 meters.
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BlueMax49ers was founded to combat unreliable USB programming cables for radios. Offering high-quality cables with premium components, BlueMax49ers ensures dependable radio programming and interfacing. Their Software Advisor aids in finding compatible software, ensuring a 99.9% success rate. With two decades of expertise, BlueMax49ers provides reliable solutions for all radio programming needs.
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The Gemini Amplifier Remote Control software operates on Windows 7 and above, facilitating remote management of the Gemini HF-1K and DX-1200 amplifiers. Users connect via Ethernet, configuring the amplifier's IP address through the front panel. The software allows seamless band and antenna selection, saving settings for each band without requiring transmission. Integration with _OmniRig_ from Afreet Software, Inc. enables automatic band adjustments based on the radio's frequency changes. Users can configure serial or virtual serial connections, with tracking options accessible through the ribbon bar. The software supports speech functionality, enhancing accessibility for operators. Firmware updates, such as version 2.5Ee, introduce features like background datalogging and power output control, uploaded via FTP. Version 1.2.0 allows users to offload internal parameter data for support purposes. The firmware upload process requires the amplifier's IP address and port 21, taking approximately 90 seconds. Users are encouraged to upgrade to the latest firmware for improved performance and remote diagnostics.
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The International DX Amateur Radio Club provides a structured environment for amateur radio operators interested in long-distance communication. The club offers a variety of awards, including the DX Countries Award, DX United States Award, and DX Continents Award, among others. These awards recognize achievements in contacting stations across different geographical areas, such as Europe, Africa, South America, and Asia. The club also supplies resources like DX Spots, Grey Line Map, and Solar Data to assist operators in optimizing their communication strategies. The DX Code of Conduct emphasizes disciplined operating practices. Operators are encouraged to listen carefully before transmitting and ensure they have correctly identified the DX station's call sign. The guidelines advise against interfering with ongoing communications and stress the importance of patience, such as waiting for the DX station to complete a contact before calling. Operators are reminded to send their full call sign and avoid continuous calling, maintaining respect for fellow operators to foster a cooperative amateur radio community. DXZone Technical Profile: DX Awards | DX Code of Conduct | Grey Line Map